Control valve



A. J. KNUDTSON 3,521,601

CONTROL VALVE July 28, 1970 2 Sheets-Sheet 1 Filed Oct. 2 8, 1968 1 INVENTOR jmafJ KNUDEOM BY g ATTORNEE July 28, 1970 A. J. KNUDTSON 3,521,601

. CONTROL VALVE Filed Oct. 28. 1968 z'sheets-sheet 2 MMZ M A'ITORNEYS United States Patent 3,521,601 CONTROL VALVE Arthur Jewell Knudtson, 1880 Pacific Highway 5., Junction City, Oreg. 97448 Filed Oct. 28, 1968, Ser. No. 771,229 Int. Cl. Bc 11/00 U.S. Cl. 1188 4 Claims ABSTRACT OF THE DISCLOSURE A depressed area filling device has a valve disposed in the dispensing outlet. The valve is directly acted upon by the filling medium in both the feed line and at the dispensing outlet and the pressure differential thereof actuates the valve for both the filling and closing functions.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to the filling of imperfections in the edges and surfaces of plywood sheets so that all edges and surfaces are uniform. The invention consists of a valve structure in the applicator which is arranged to permit the flow of filler when imperfections underlie the applicator and to shut off the flow of filler when there are no imperfections present. The valve is actuated by the fiow pressure of the filler material and back pressure of the filler material.

Description of the prior art In prior art devices, the flow of material is controlled by the pressure applied to the material, and a film of filler is coated onto the good surfaces of the plywood when sufficient pressure to fill the imperfections is used. The present invention is to be used in association with a device such as that illustrated in U.S. patents to S. B. Knudtson (No. 3,362,379, issued Jan. 9, 1968) and G. F. Neils (No. 2,335,528, issued Nov. 30, 1943, and No. 2,392,827, issued Jan. 15, 1946).

SUMMARY OF THE INVENTION The present invention includes a valve structure which is actuated by the fiow of filler so that so long as there is a defect to be filled underlying the device, filler will flow through and pass the valve and completely fill the defect. When the defect is filled, back pressure on the filler will cause the valve to close so that no further flow of filler will take place until another defect is encountered.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of the invention;

FIG. 2 is a bottom plan view of the invention;

FIG. 3 is a top plan view of the invention;

FIG. 4 is a vertical cross-section taken along the line 44 of FIG. 1 looking in the direction of the arrows;

FIG. 5 is a vertical cross-section taken along the line 55 of FIG. 4 looking in the direction of the arrows with the valve in open position and filler flowing therearound; and

FIG. 6 is a view similar to FIG. 5 with the valve in closed position with no crevice underlying the filler.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail wherein like reference characters indicate like parts throughout the several figures the reference numeral 10 indicates generally a valve assembly for use in a device for detecting and filling defects in side edges and face surfaces of plywood panels.

The valve assembly 10 is used in an apparatus such as that illustrated in the Knudtson Pat. 3,362,379 wherein a sheet of plywood is caused to move past a device for detecting and filling defects in the side edges and face surfaces thereof. The valve assembly 10 includes a generally rectangular body 11 having a bottom surface 12 adapted to engage the plywood panel 13 along one edge thereof. The plywood panel 13 has irregular surface defects 14 which need to be filled with a wood filler.

The body 11 is shouldered as at 15 for engagement in the filling device, and an upwardly tapered leading edge 16 is provided on the flat lower surface 12 to guide the body 11 over the surface of the plywood 13.

A bore 17 opens from the top of the body 11 and extends downwardly through the body 11 to a shoulder 18 which is parallel and spaced from the flat surface 12. A transverse slot 19 extends from side to side of the body 11 transversely thereof intermediate the opposite ends and intersects the bore 17 centrally thereof. The bore 17 is internally threaded at 20' for reasons to be assigned.

A cylindrical tubular insert sleeve 21 is slidably mounted in the bore 17 and engages the shoulder 18 at the bottom of the bore 17. A port extension 22 is in tegrally formed with the lower end of the insert sleeve 21 and is shaped to fit the slot 19 so that its hardened lower surface 23 normally coincides with the surface 12 of the body 11. The port extension 22 has an elongated port 24 formed therein and communicating with a tapered conduit 25 extending downwardly from the lower end of the bore 26 in the tubular insert sleeve 21.

The insert sleeve 21 is spring urged downwardly in the bore 17 by a spring 27 engaging the top of the sleeve 21 secured in place by a spring retainer nut 28 threaded into the threads 20 of the body 11. The spring retainer nut 28 has a bore 29 coaxial with the bore 26 and having the same diameter as the bore 26.

A cylindrical tubular valve body 30 extends through the bore 26 from the lower end thereof upwardly through the bore 29 as can be seen in FIGS. 5 and 6. The tubular valve body 30 has a central bore 31 opening into an expanded internally threaded bore 32 at its upper end and into a counterbore 33 at its lower end. The counterbore 33 opens through the lower end of the valve body 30 and has a diameter substantially greater than the diameter of the bore 31. A set screw 34 extends through the insert sleeve 21 into the tubular valve body 30 to lock the valve body 30 to the insert sleeve 21. A milled relief groove 35 is formed in the insert sleeve 21 from the lower end of the bore 26 to a point adjacent the upper end of the bore 26, but short of the upper end of the bore 26. A port 36 in the valve body 30 communicates the upper end of the groove 35 with the bore 31 at a point intermediate the opposite ends of the valve body 30. A port 37 through the valve body 30 communicates the lower end of the groove 35 with the lower end of the bore 33 for reasons to be assigned.

A fitting 38 is threaded into the threaded bore 32 to connect to a source of filler supply (not shown). A free piston 39 is mounted in the counterbore 33 for reciprocation therein and a second free piston 40 is mounted in the bore 31 for reciprocation therein. The free pistons 39 and 40 may be either integral or two pieces, as desired.

A set screw 41 extends through the insert sleeve 21 at the lower end thereof and extends upwardly into the counterbore 33 to support the piston 39 above the port 37 for reasons to be assigned.

In the use and operation of the invention, the body 11 is positioned with the surface 12 in contact with a sheet of plywood 13. The plywood 13 is moved under the body 11 until a defect 14 requiring filling underlies the elongated slot 24 of the insert sleeve 21. Filler under pressure is fed through the fitting 38 into the bore 31 where it presses downwardly on the cylinder 40 so that the upper 3 end of the cylinder 40 clears the port 36 whereupon the finer" flows'through"the""port'36 down the groove 35" through the port 37 and into the counterbore 33 downwardly through the elongated port 24 into the defect 14. As the defect 14 becomes full of filler, back pressure develops in the counterbore 33 and since the piston 39 is larger than the piston 40 it raises in the counterbore 33 and presses the piston 40 upwardly until the upper end of the piston 40 covers the port 36 shutting off the flow of filler through the port 24. The ports stay in this position until another defect is encountered whereupon pressure drops in the counterbore 33 and port 24 so that the pressure on the piston 40 is sufiicient to overcome the pressure on the piston 39 and hence the pistons 40 and 39 move downwardly uncovering the port 36 and permitting flow of filler to again take place until the new defect is filled.

A bleeder port 42 opens through the body 11, insert sleeve 21, and valve body 30 communicating with the upper end of the counterbore 33 to bleed the counterbore 33 which permits the piston 39 to reciprocate therein without developing a head pressure at its upper end.

Having thus described the preferred embodiment of the invention, it should be understood that numerous structural modifications and adaptations may be resorted to without departing from the spirit of the invention.

I claim:

1. A control valve assembly for controlling the flow of filling material in a plywood defect filling device comprising:

a body having a vertical bore extending downwardly therein and terminating short of the lower surface of said body, said body having a transverse slot at the lower portion thereof extending completely thereacross and intersecting said bore and a lower surface of said body;

an insert sleeve resiliently mounted in said bore and having an extension projecting into said slot terminating normally in a plane with the lower surface of said body, said extension having an elongated port formed therein for feeding filler material to a plywood defect underlying said body;

a tubular valve body disposed Within said sleeve and connecting said elongated port with a source of filler material under pressure;

means controlled by the pressure of said filler material v 4 V J ,p a fa n e u n e 119 3 .95 fi l r. mate ial. sheath? plywood defect has been filled; and said last means comprising a piston valve slidably mounted in said tubular valve body and an actuator piston having a diameter substantially greater than said piston valve slidably mounted in said valve body in engagement with said piston valve whereby said pressure of the filler material acts onsaid actuator piston to move said piston valve into closed position interrupting the supply of filler material to said port. 2. A device as set forth in claim 1 wherein said valve body includes a counterbore at its lower end within which said actuator piston moves, and bleeder means are provided for venting the upper portion of said counterbore for preventing development of a head pressure above said actuator piston. V p

3. A device as claimed in claim 1 wherein the lower end of said extension is hardened for engagement with the surface of said plywood.

4. A device as claimed in claim 1 wherein said valve body is releasably locked into said insert sleeve.

References Cited UNITED STATES PATENTS 1,290,968 1/1919 Gillette 14195 1,917,316 7/1933 Naab 137505.22 X 2,697,253 12/1954 Kruft 118-410 X 2,765,494 10/1956 Weingart 118410'X 2,986,776 6/1961 Frohring 18-30 3,005,475 10/1961 Beall 141-498 3,355,144 11/1967 Knudtson 251322 3,362,379 1/1968 Knudtson 1188 3,363,641 1/1968 Mylander 141-192 X 3,374,803 3/1968 Leveque 137-503 FOREIGN PATENTS 788,818 1/1958 Great Britain. 970,419 9/1964 Great Britain.

MORRIS KAPLAN, Primary Examiner US. Cl. X.R. 1442; 118-410 

